Lochinvar® has enhanced the Power-Fin® commercial water heaters and boilers for greater installation flexibility. Models feature digital temperature control, gasketless copper tube heat exchanger, multiple venting solutions, and low NOx operation. All models, from 500,000 to 2.0 Million Btu/hr, operate at up to 88% thermal efficiency. The fan-assisted burner system can be specified as on/off fire (500,000 to 1,300,000 Btu/hr), or infinitely proportional firing from 50% to 100% with pinpoint control (all models). Lochinvar®.